The reason why Luo Dalun's books were banned may be the copyright issue. Copyright is the legal ownership of the right to copy computer programs, literary works, musical works, photos, games, movies and so on. In most countries, copyright is only protected for 50 years after the death of the author. But in some countries, such as Chinese mainland, there is no such regulation, that is, there is no time limit. In addition, copyright may be related to moral or political issues, so some countries may restrict the copyright of certain works. In addition, some books may be banned because they contain controversial contents, such as racial discrimination, gender discrimination, sexual abuse and so on. Therefore, the specific reasons why books in Luo Dalun are banned may need to refer to the copyright regulations of specific countries and regions and the contents contained in the books.